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Vegan Green Bean Casserole

Vegan green bean casserole combines crisp-tender green beans with a creamy mushroom sauce, baked until bubbling and topped with golden crispy fried onions. This oven-baked side is made with oat milk and serves eight.
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Prep Time 20 minutes
Cook Time 50 minutes
Resting 5 minutes
Total Time 1 hour 15 minutes
Servings: 8 servings
Course: Side Dish
Cuisine: American
Calories: 230
Ingredients Equipment Method Notes

Ingredients
  

For the casserole
  • 1 tsp olive oil for greasing
For the green beans
  • 2 lb green beans fresh, trimmed and cut into 2-inch pieces
For the mushroom sauce
  • 3 tbsp olive oil
  • 1 yellow onion medium, finely chopped
  • 12 oz cremini mushrooms sliced
  • 2 cloves garlic minced
  • 0.25 cup all-purpose flour
  • 2 cups vegetable broth
  • 1 cup oat milk unsweetened plain
  • 1 tbsp soy sauce
  • 0.5 tsp kosher salt
  • 0.25 tsp black pepper
For the topping
  • 1.5 cups vegan crispy fried onions

Equipment

  • 1 9x13-inch baking dish
  • 1 12-inch skillet

Method
 

Prepare the casserole
  1. Heat the oven to 375°F.
  2. Grease a 9x13-inch baking dish with 1 teaspoon olive oil.
Blanch the green beans
  1. Bring a large pot of water to a boil.
  2. Add the green beans and cook for 4 to 5 minutes until bright green and crisp-tender.
  3. Drain the green beans, rinse under cold water, and drain well.
Make the mushroom sauce
  1. Heat 3 tablespoons olive oil in a 12-inch skillet over medium heat.
  2. Add the onion and mushrooms, and cook for 8 to 10 minutes, stirring occasionally, until the mushrooms are browned and their liquid has evaporated.
  3. Stir in the garlic and cook for 30 seconds.
  4. Stir in the flour and cook for 1 minute.
  5. Gradually whisk in the vegetable broth and oat milk until smooth.
  6. Stir in the soy sauce, salt, and pepper.
  7. Simmer for 4 to 6 minutes, stirring, until thick enough to coat a spoon.
Assemble and bake
  1. Add the green beans to the prepared baking dish, pour the mushroom sauce over them, and stir until evenly coated.
  2. Bake for 20 to 25 minutes until bubbling around the edges.
  3. Scatter the crispy fried onions evenly over the top.
  4. Bake for another 5 to 8 minutes until golden.
  5. Rest the casserole for 5 minutes before serving.

Notes

Drain the green beans well so the sauce stays creamy. Refrigerate leftovers for 3 to 4 days; freezing is not recommended because the crispy onions lose their texture. For a gluten-free version, use gluten-free flour and crispy onions and replace the soy sauce with tamari.